DAX

Skills and references for writing, debugging, and optimizing DAX in semantic models.

Object references

Write column references as 'Table'[Column]: the table name is always present and always in single quotes. Write measure references as [Measure], never prefixed with a table. This applies everywhere DAX or model metadata names an object: measure, calculated column and calculation item expressions, RLS filters, format string expressions, DAX queries (te query, pbir model -q), and descriptions or annotations that mention an object.

Why: a measure belongs to the model rather than to its home table, so moving it between tables must not change any expression that uses it; a bare [Measure] also tells the reader at a glance that it is a measure and not a column. An unqualified column is ambiguous as soon as two tables share a column name, and quoting every table name keeps one consistent form whether or not the name needs quotes.

Optimization

For systematic DAX query performance optimization, read the workflow reference first:

references/dax-performance-optimization.md — Tiered framework (4 tiers), phased workflow, decision guide, and error handling.

Detailed reference files (progressive disclosure — consult as directed by the workflow):